Engineering • Accessibility • Web Standards

HTML Accessibility Checker: 10 Common WCAG Issues You Can Fix Today

Accessibility is not just a compliance checkbox; it is a way to make your website easier for everyone to use. The good news is that many accessibility problems come from a small set of common HTML issues, and most of them are quick to fix once you know what to look for.

This guide walks through 10 frequent WCAG issues that accessibility checkers often flag, explains why they matter, and shows you how to fix them in practical, developer-friendly terms. If you build or maintain websites, these are the first problems worth solving because they give you the biggest improvement for the least effort.

The goal is simple: make your pages more usable for keyboard users, screen reader users, people with low vision, and anyone who benefits from clearer structure and better interaction patterns.

1. Missing alt text on images

Images without meaningful alt text are one of the most common accessibility failures. Screen reader users may hear that an image exists, but they will not know what it shows or why it matters.

The fix is simple: add descriptive alt text for informative images, and use empty alt text for decorative ones. That way, assistive technology can skip unimportant images and read the useful ones properly.

• Good – alt="Team meeting in a conference room"
• Decorative – alt=""
• Avoid – vague text like “image” or “photo”

2. Low color contrast

Text that blends too closely with the background is hard to read, especially for users with low vision or users on mobile devices in bright light. Contrast problems often show up in light gray text, thin button labels, and text overlays on images.

WCAG requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text. A contrast checker can help you verify color combinations before they go live.

3. No keyboard access

If users cannot use Tab, Enter, Space, and arrow keys to reach and operate controls, the page is not fully accessible. This often affects custom dropdowns, menus, modals, sliders, and clickable elements built with plain divs.

Every interactive element should be focusable and operable from the keyboard. Native HTML elements like button, a, input, and select usually solve this better than custom replacements.

• Use real buttons for actions.
• Use links for navigation.
• Test your site without a mouse.

4. Missing form labels

Forms without proper labels force users to guess what each field means. Screen readers also rely on labels to announce the purpose of inputs clearly, which makes labels essential for accessibility.

The best fix is to connect each input to a visible label using the label element. Placeholders are not a substitute because they disappear as soon as the user types.

For example, an email field should have a label like “Email address,” not just placeholder text inside the box.

5. Poor heading structure

Headings are not just visual styling; they create a content outline that helps users navigate a page. Skipping heading levels or using headings out of order can confuse screen reader users and make the page harder to scan.

Keep the hierarchy logical: one h1 for the page title, then h2 sections, then h3 subsections when needed. Avoid using heading tags just because they look bigger or bolder.

• Use headings in order.
• Do not skip from h1 to h3 without a reason.
• Do not style normal text as a heading.

6. Empty links and buttons

Links and buttons that contain only an icon or no readable text are often announced poorly by screen readers. A button that only says “button” gives no useful information about what it does.

Add visible text or an accessible name using aria-label when necessary. In most cases, visible text is still the best solution because it helps everyone, not only assistive technology users.

Descriptive link text is also better than generic phrases like “click here” or “read more.”

7. Missing page language

Without a language declaration, screen readers may pronounce text incorrectly. That can make content harder to understand, especially on multilingual sites or sites with custom pronunciations.

The fix is straightforward: declare the language in the HTML tag, such as . If a page contains a different language section, mark that content appropriately too.

8. Hidden or weak focus indicators

Keyboard users need a visible focus state to know where they are on the page. If focus outlines are removed without a replacement, navigation becomes frustrating and unreliable.

Many modern stylesheets accidentally hide focus by setting outline: none globally. Avoid doing that unless you provide a strong, visible alternative that is at least as easy to see.

• Keep a strong focus ring.
• Do not remove focus styles sitewide.
• Make focus easy to see on buttons, links, and inputs.

9. Inaccessible menus and dropdowns

Menus that only open on hover create problems for keyboard and touch users. They can also break when users move focus quickly or try to close the menu with Escape.

Accessible menus should open with click or keyboard, expose their state properly, and allow navigation without requiring a mouse. Native details, button, and list patterns often work better than custom hover-only solutions.

If you use ARIA here, use it carefully and only when native HTML cannot do the job.

10. Videos without captions

Video content without captions excludes deaf and hard-of-hearing users, and it also hurts anyone watching in a noisy or silent environment. Captions make video content more flexible and searchable too.

Add accurate closed captions to all important video content, and provide transcripts when possible. Auto-generated captions are a useful start, but they should be reviewed for mistakes.

How to fix issues faster

The fastest way to improve accessibility is to focus on the basics first. Fixing alt text, contrast, labels, headings, and keyboard access will eliminate a large share of common problems on most sites.

After that, test your pages with a keyboard, check the structure with a screen reader, and scan the HTML for obvious semantic issues. A checker is useful, but manual review is what catches the mistakes that automation misses.

1. Start with the most common issues.
2. Fix semantic HTML first.
3. Check keyboard navigation manually.
4. Review forms and media content.
5. Retest after every update.

Why this matters today

Accessibility improvements do more than help users with disabilities. They also improve usability for people on mobile devices, slow connections, noisy environments, and older hardware.

Better accessibility often means clearer structure, better UX, and fewer support problems. In practice, that makes the whole site stronger.

Final takeaway

Most WCAG issues are not hard to fix once you know where to look. If you tackle the ten common problems in this guide, you will make immediate progress toward a more accessible and more reliable website.

The best approach is simple: build with semantic HTML, test with the keyboard, keep contrast readable, label your forms, and make media understandable. Those habits go a long way toward creating a better web for everyone.